The Green Economy is an alternative vision for growth and development; one that can generate economic development and improvements in people’s lives in ways consistent with advancing also environmental and social well-being. One significant component of a green economy strategy is to promote the development and adoption of sustainable technologies. The overall objective of this article is to discuss a number of challenges encountered when pursuing sustainable technological change, and that need to be properly understood by policy makers and professionals at different levels in society. We also identify some avenues for future research. The discussions center on five challenges: (a) dealing with diffuse – and ever more global – environmental risks; (b) achieving radical and not just incremental sustainable technological change; (c) green capitalism and the uncertain business-as-usual scenario; (d) the role of the state and designing appropriate policy mixes; and (e) dealing with distributional concerns and impacts. The article argues that sustainable technological change will require a re-assessment of the roles of the private industry and the state, respectively, and that future research should increasingly address the challenges of identifying and implementing novel policy instrument combinations in various institutional contexts.

The objective of this paper is to review previous research on convergence of carbon dioxide emissions among countries. We discuss the key findings in this work, how the choices of model, data, statistical tests, etc. influence the results, and highlight some policy implications. The empirical research on convergence in per capita carbon dioxide emissions shows some evidence of convergence between developed (OECD) countries, while at the global level there appear to be relatively persistent gaps or divergence. These results are however sensitive to the choice of econometric approach and data set (e.g., the length of the time series). Still, the empirical basis for an egalitarian rule of equal per capita emissions in the design of global climate policy is not solid; it ignores the specific structural characteristics of countries such as climate, natural resource endowments, etc. The analysis therefore points to a need for more in-depth analyses of the structural determinants of carbon intensity (productivity) at the country level, as well as to additional research on the economic consequences of different types of equity principles (including combinations of such principles).

While there is relatively limited disagreement on the general need for supporting the deployment of renewable energy sources for electricity generation (RES-E), there are diverging views on whether the granted support levels should be technology-neutral or technology-specific. In this review paper we question the frequently stressed argument that technology-neutral schemes will promote RES-E deployment cost-effectively. We use a simple partial equilibrium model of the electricity sector with one representative investor as a vehicle to synthesize the existing literature, and review potential rationales for technology-specific RES-E support. The analysis addresses market failures associated with technological development, long-term risk taking, path dependencies as well as various external costs, all of which drive a wedge between the private and the social costs of RES-E deployment. Based on analytical insight and a review of empirical literature, we conclude that the relevance of these market failures is typically heterogeneous across different RES-E technologies. The paper also discusses a number of possible caveats to implementing cost-effective technology-specific support schemes in practice, including the role of various informational and politico-economic constraints. While these considerations involve important challenges, neither of them suggests an unambiguous plea for technology-neutral RES-E support policies either. We close by highlighting principles for careful RES-E policy design, and by outlining four important avenues for future research.

Biofuels and biochemicals play significant roles in the transition towards a fossil-free society. However, large-scale biorefineries are not yet cost-competitive with their fossil-fuel counterparts, and it is important to identify biorefinery concepts with high economic performance. For evaluating early-stage biorefinery concepts, one needs to consider not only the technical performance and process costs but also the economic performance of the full supply chain and the impacts on feedstock and product markets. This article presents and demonstrates a conceptual interdisciplinary framework that can constitute the basis for evaluations of the full supply-chain performance of biorefinery concepts. This framework considers the competition for biomass across sectors, assumes exogenous end-use product demand, and incorporates various geographical and technical constraints. The framework is demonstrated empirically through a case study of a sawmill-integrated biorefinery producing liquefied biomethane from forestry and forest industry residues. The case study results illustrate that acknowledging biomass market effects in the supply chain evaluation implies changes in both biomass prices and the allocation of biomass across sectors. The proposed framework should facilitate the identification of biorefinery concepts with a high economic performance which are robust to feedstock price changes caused by the increase in biomass demand.